Samuel v



(No Model.)

B. CLARK, Deod.

S. V. HARRON, Administrator, ELECTRIC CONDUCTOR.

No. 437,568. Patented Sept. 30, 1890.

BAMBOO SM vamto'c wibvbeooeg UNITED STATES PATENT OFFICE.

EDIVARD CLARK, OF NEIVBURG, ORANGE COUNTY, NE\V YORK; SAMUEL V. HARRON ADMINISTRATOR OF SAID EDWARD CLARK, DECEASED.

ELECTRIC CONDUCTOR.

SPECIFICATION forming part of Letters Patent No. 437,568, dated September 30, 1890.

Application filed May 15, 1889. Serial No. 310,319- No model.)

To all whom it may concern:

Be it known that I, EDWARD CLARK, a citizen of the United States, residing at Newburgh, county of Orange, State of New York,

have invented a new and useful Improvement in Electrical Conductors, of which the following is a full, clear, and exact specification.

My invention relates to electric conductors;

and it has for its obj eat to provide an electric conductor that shall be thoroughly insulated, and at the same time sufficiently flexible to permit of its being used under all necessary conditions without danger of rupturing the insulation and to be able to withstand to a greater degree thanis common the ordinary Wear and tear upon its surface.

To this end my invention consists in an electric conductor constructed substantially as specified hereinafter.

In the accompanying drawing I have shown an electric conductor covered with an insulating and protecting material under various conditions involving my invention.

2 5 In the manufacture of electric conductors one of the most important features consists in providing a conductor which while it is properly and thoroughly insulated is at the same time sufficiently flexible to adapt it to 0 all the necessary bendings incident to its use under all conditions, and this Without danger of rupturing or destroying the insulation. Many and various ways of accomplishing these results have been suggested, some of which have been more or less successful and practical; but it has been found exceedingly diffioult to have the conductor thoroughly insulated and still retain the desired amount of flexibility. By my invention I am enabled to attain these results to a most satisfactory degree, and I will now proceed to describe what I consider to be the best means of carrying out my invention.

I take a wire or conductor A, which may be naked or covered with the usual braid covering B, and I coat this with aliquid asphaltum varnish, and this forms a basis for the other coating which I apply to the conductor. This coating is preferably applied as thin as pos 5o sible, but sufficient to thoroughly cover the wire or saturate the braid covering thereof so that all the interstices are thoroughly filled and air and moisture excluded therefrom. Over this coating I wrap a tape 0 spirally around the conductor. This tape has selvage edges on both sides, and before being applied is saturated with the asphaltum varnish by beingpassedthroughavatcontainingthe same or in any other suitable Way. This varnish should be applied to the table so as to leave as thin a coating thereon as is practical, care being taken that it is thoroughly permeated therewith through all its parts, and then when it is wrapped round and round the conductor, with its edges overlapping it, forms a thin but practically impervious wrapper, and at the same time it permits the conductor being bent without breaking or destroying the insulation. Over this spirally-wound tape I apply a thin coatingD of a mixture composed, 7o essentially, of asphaltum varnish, mineral wool, and pulverized slipperyelm bark. While this mixture may be made in various proportions, I preferably use about three parts of asphaltum varnish to one part of mineral wool and slippery-elm bark, combined in equal proportions, and these ingredients are previously thoroughly commingled and mixed by heating the varnish to the required degree of fluidity, or stirring them until an even and smooth mixture is produced. I use the slippery-elm bark more especially for its fibrous qualities to render the mixture sufficiently cohesive, as Well as for its drying qualities, to prevent any moisture being absorbed by the mixture, and the mineral Wool is added not only for its fibrous and drying qualities, but to render the mixture practi cally fire-proof. After this coating of the above-described mixture has been applied, a 0 thin coating of asphaltum varnish may be put on to cover up any unevenness or fill any pores that may appear in the coating. The conductor is then covered with a thread or cord E, composed of tar marline, which has 5 previously been thoroughly saturated with varnish, and this thread or cord is closely coiled round and round in a spiral form over the coating of mixture before applied.

The tar marline while it has the quality of hemp thread or cord, saturated, as before,

with asphaltum, and, if desired, a thin coatin g of asphaltum varnish may be applied over all. The conductor in this form is then preferably polished or rubbed with pulverized soapstoneor equivalent material to give it a desirable surface and to remove the sticking qualities, so that the different portions of the conductor will not adhere to each other, and when it is to be used for inside work I preferably use it in this condition. When, however, the conductor is to be used for outside work orfor submarine purposes and the like, Icover it with .a protective cover G, made of leather, wire, string lead, or strips of bamboo or rattan, and this cover is applied in the form of a spiral winding round and round the conductor. While all these materials may be usedaccordingto the purpose for which it is desired, I have found that bamboo strips constitute one of the best and most eflicient protecting coverings, owing to the extreme hardness of the outside coating or skin of the natural bamboo, it being understood, of course, that this natural covering is cut off in strips and so applied that the skin is upon the outside. More than this, the natural curved surface of this bamboo or rattan fur nishes a good bearing-surface for the .conductor, as well as a high polish. Sometimes I found it-desirable to cover the whole with a layer of asbestus H in the form of strips wound .spirally over the conductor to make it absolutely fire-proof.

From the above it will be seen that I am enabled to produce an insulating-coating which is practically impervious. to moisture, and which, being applied in the for-m of spirals wrapped round and round the conductor, it is extremely flexible and may be bent to com ply with all the ordinary conditions under which it is to be used. By making the various coatings as thin as possible the-thickness of the insulation is kept within practical bounds, while at the same time it is sufficient to thoroughly protect the conductor under any currents which may be passed through the the same.

What I claim is- 1. An electricconductor having a covering of bamboo or rattan, the hard outer surface of which is outward,substantially as described.

2. An electric conductor covered with insulatin g material having an outside wrapping of bamboo strips arranged spirally around the same, the hard outer surface of which is placed outward, substantially as described.

3. An electric conductor having an insulating-coating composed of asphaltum varnish, mineral wool, and pulverized slippery elm, a wrapping of tar marline-cord saturated with asphaltum andarranged spirally around the conductor, and an outside protecting-wrap- .ping of strips of bamboo, the hard :outer surface of which is placedoutward. H 4. An electric conductor-provided with a coating of asphaltum, an absorbent-insulating-coating of a mixture of asphaltum, mineral wool, pulverized slippery-elm bark, and tape saturated with insulating material Wound spirally around thesame, layerof tar-marline-cord saturated with an, insulating-material, acoating ofxflax cord also wound spi rally around the conductor, and an, outside protecting-coating composedof bamboo-strips or equivalent material, substantially-as described. 1. V f

In testimony whereof I have signed my name to this specification in the presence of twosubscribing witnesses.

EDWARD CLARK.

Witnesses:

- J S. BARKER,

F. L. FREEMAN. 

